[PATCH] Fix checked arithmetic for i8 on X86

[Andrea Di Biagio]

Hi Keno,

Thanks for the patch.
Can you add a test for it? I think you can probably reuse the example you posted on the bugzilla to verify that we correctly test and branch.

================
Comment at: lib/Target/X86/X86ISelLowering.cpp:11472-11474
@@ -11471,3 +11471,5 @@
   if (addTest) {
-    CC = DAG.getConstant(X86::COND_NE, MVT::i8);
-    Cond = EmitTest(Cond, X86::COND_NE, dl, DAG);
+    X86::CondCode X86Cond = X86::COND_NE;
+    if (Inverted)
+      X86Cond = X86::GetOppositeBranchCondition((X86::CondCode)X86Cond);
+    CC = DAG.getConstant(X86Cond, MVT::i8);
----------------
You can simplify this into:



  X86::CondCode X86Cond = Inverted ? X86::COND_E : X86::COND_NE;

http://reviews.llvm.org/D3920